Recording apparatus, recording method, reproducing apparatus, reproducing method, and record medium

ABSTRACT

A recording apparatus for recoding digital data to a record medium that is removable and assigned unique medium identification information is disclosed, that comprises a converting means for converting data to be recorded into a file structure that allows a first file format and a second file format to be used, the first file format being handled by computer software and composed of a reference information storing portion and a real data storing portion, the second file format being composed of only a reference information storing portion, and a recording means for recording data having the file structure to the record medium, wherein reference file information and medium identification information of the record medium or information of which the medium identification information has been converted are recorded to at least the reference information storing portion of a file having the second file format.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording apparatus, a recordingmethod, a reproducing apparatus, a reproducing method, and a recordmedium, in particular, to those corresponding to a multimedia formatsuch as QuickTime.

2. Description of the Related Art

To handle data recorded by a recording and reproducing apparatus havinga built-in camera, a digital audio reorder, or the like, a file formatcorresponding to a computer process is considered. For example, assystem software corresponding to multimedia, QuickTime is known.QuickTime is software that handles data that varies on time base (suchdata is referred to as movie). Generally speaking, QuickTime is an OS'sextended function that allows a moving picture to be reproduced withoutneed to dedicated hardware. In QuickTime, various data formats can behandled. In other words, up to 32 tracks of outputs of audio data,moving picture, MDI, and so forth can be synchronized.

A QuickTime movie file is largely divided into two portions that are amovie resource portion and a movie data portion. The movie resourceportion contains information representing the reproduction duration ofthe QuickTime file and reference information for referencing the realdata. The movie data portion contains video real data and audio realdata.

With a video fila and an audio file having such a file format containingthe real data storing portion and the reference information storingportion, video data and audio data can be edited as a non-linear editingoperation. In this case, both the storing portions may be oftencontained in one file as a video file or a audio file. In other words,by reading such a file, real data and a reproducing method thereof canbe obtained. Such a file is referred to as self-contained type file(first file format).

In another format of a file created by editing a video file and an audiofile are edited, after the video file and the audio file are edited,real data and a reference information storing portion are newly createdand contained in one file. For example, when two files are combined andthereby a new file is created, the new file is composed of a real datastoring portion and a reference information storing portion of which theoriginal two files have been combined. In this editing method, originaldata may be lost. In addition, as files are edited, a large amount ofdata should be rewritten. Thus, it takes a long time to perform theediting process. When the original data is stored as it is, both theoriginal data and the edited data are stored. As a result, therecordable capacity of the data record medium decreases.

To solve such a problem, a file that contains only a referenceinformation storing portion that allows only a required portion to bereferenced from a real data portion of an existing file may be newlycreated and edited. In this method, a file that contains only areference information storing portion as an edited result is recorded toa record medium. A file that contains only a reference informationstoring portion for referencing external real data is referred to asexternal-referenced type file (second file format). In the case of theexternal-referenced type file, a description that designates a file thatcontains a real data portion that is referenced is required (thisdescription is referred to as reference file information). In the secondfile format, unlike with the first file format of which a file containsboth a reference information storing portion as an edited result and areal data storing portion, the editing time does not become long. Inaddition, a problem of which original data is not lost does not takeplace.

FIG. 16 shows a concept of the state of which a self-contained type file102, which contains a movie resource portion and a movie data portion,and an external-referenced type file 103, which contains only a movieresource portion, have been recorded on a rewritable optical disc 101.The optical disc 101 is a removable disc (attachable and detachable).Thus, a situation of which data of a plurality of optical discs isedited by a personal computer 121 shown in FIG. 17 can be considered.

In FIG. 17, reference numeral 111 represents an optical disc recordersuch as a disc recording and reproducing apparatus having a built-incamera or a digital audio recorder. A conventional recorder normally hasa reproducing function. The optical disc recorder 111 records video dataand audio data to optical discs 101 a, 101 b, and so forth. Theseoptical discs 101 a, 101 b, and so forth are inserted into a drive ofthe personal computer 121. A plurality of files of the optical discs 101a, 101 b, and so forth are read to a hard disk 122 of the personalcomputer 121. Such an operation is referred to as copy or move. The copyis an operation that allows data of the copy source to remain. Incontrast, the move is an operation that allows data of the copy sourcenot to remain. Real data (a movie data portion) of a file is not read tothe personal computer 121. Instead, only reference information (a movieresource portion) is read to the personal computer 121.

The personal computer 121 pre-installs QuickTime as software. The useredits data on QuickTime. Thereafter, the user copies or moves the editedresult to the optical disc 101 c. The data recorded on the optical disc101 c is reproduced by a recorder 111. The edited result is recorded inthe above-described external-referenced type file format to the opticaldisc 101 c. A reproduction corresponding to the edited result isreferred to as program reproduction.

In the method for storing the edited result in the external-referencedtype file format, a description should uniquely designate a file to bereferenced. In the system shown in FIG. 17, when a file is read from oneoptical disc to the personal computer 121 and the edited result isrewritten to the same optical disc, a problem of which an unintendedfile is referenced does not take place.

However, when the edited result is mistakenly copied or moved to animproper disc and the disc contains the same identification information(for example, file name) as that of the movie file to be referenced, aprogram of which a program irrespective of the edited result isreproduced takes place. In addition, when data of a plurality of opticaldiscs 101 a, 101 b, and so forth is read to the hard disk 122 of thepersonal computer 121 and the data is edited, files that are read fromdifferent optical discs may have the same identification information. Asa result, the edited result stored in the external-referenced type fileformat may designate an unintended file.

OBJECTS AND SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to prove a recordingapparatus, a recording method, a reproducing apparatus, a reproducingmethod, and a record medium that allow an unintended file to beprevented from being referenced upon recording data in a file structurehaving a real data storing portion and a reference information storingportion corresponding to a multimedia data format such as QuickTime.

A first aspect of the present invention is a recording apparatus forrecoding digital data to a record medium that is removable and assignedunique medium identification information, comprising a converting meansfor converting data to be recorded into a file structure that allows afirst file format and a second file format to be used, the first fileformat being handled by computer software and composed of a referenceinformation storing portion and a real data storing portion, the secondfile format being composed of only a reference information storingportion, and a recording means for recording data having the filestructure to the record medium, wherein reference file information andmedium identification information of the record medium or information ofwhich the medium identification information has been converted arerecorded to at least the reference information storing portion of a filehaving the second file format.

A second aspect of the present invention is a recording apparatus forrecording digital data to a record medium that is removable and assignedunique medium identification information in a file structure that allowsa first file format and a second file format to be used, the first fileformat being handled by computer software and composed of a referenceinformation storing portion and a real data storing portion, the secondfile format being composed of only a reference information storingportion, wherein when a file that is read from a record medium is editedand the edited result is stored to the record medium in the second fileformat, unique medium identification information of the record medium isread and the medium identification information or information of whichthe medium identification information has been converted and referencefile information are recorded to the reference information storingportion along with the edited result.

A third aspect of the present invention is a recording method forrecoding digital data to a record medium that is removable and assignedunique medium identification information, comprising the steps ofconverting data to be recorded into a file structure that allows a firstfile format and a second file format to be used, the first file formatbeing handled by computer software and composed of a referenceinformation storing portion and a real data storing portion, the secondfile format being composed of only a reference information storingportion, and recording data having the file structure to the recordmedium, wherein reference file information and medium identificationinformation of the record medium or information of which the mediumidentification information has been converted are recorded to at leastthe reference information storing portion of a file having the secondfile format.

A fourth aspect of the present invention is a recording method forrecording digital data to a record medium that is removable and assignedunique medium identification information in a file structure that allowsa first file format and a second file format to be used, the first fileformat being handled by computer software and composed of a referenceinformation storing portion and a real data storing portion, the secondfile format being composed of only a reference information storingportion, comprising the steps of when a file that is read from a recordmedium is edited and the edited result is stored to the record medium inthe second file format, reading unique medium identification informationof the record medium, and recording the medium identificationinformation or information of which the medium identificationinformation has been converted and reference file information to thereference information storing portion along with the edited result.

A fifth aspect of the present invention is a reproducing apparatus forreproducing digital data from a record medium that is removable andassigned unique medium identification information, the digital datahaving a file structure that allows a first file format and a secondfile format to be used, the first file format being handled by computersoftware and composed of a reference information storing portion and areal data storing portion, the second file format being composed of onlya reference information storing portion, reference file information andmedium identification information of the record medium or information ofwhich the medium identification information has been converted beingrecorded to at least the reference information storing portion of a filehaving the second file format, comprising a means for determining thefile format of data that is read from the record medium and forreproducing the data when the file format of the data that has been readis the first file format, a means for reading the reference fileidentification information and the medium identification information orthe information of which the medium identification information has beenconverted from the reference information storing portion when the fileformat of the data that has been read is the second file format, a meansfor reading the medium identification information or the information ofwhich the medium identification information has been converted and thereference file information from the record medium, and a means fordetermining whether or not the medium identification information or theinformation of which the medium identification information has beenconverted recorded in the reference information storing portion matchesthe medium identification information or the information of which themedium identification information has been converted recorded on therecord medium and for reading a file designated by the reference fileinformation and reproducing the file when they match.

A sixth aspect of the present invention is a reproducing method forreproducing digital data from a record medium that is removable andassigned unique medium identification information, the digital datahaving a file structure that allows a first file format and a secondfile format to be used, the first file format being handled by computersoftware and composed of a reference information storing portion and areal data storing portion, the second file format being composed of onlya reference information storing portion, reference file information andmedium identification information of the record medium or information ofwhich the medium identification information has been converted beingrecorded to at least the reference information storing portion of a filehaving the second file format, comprising the steps of determining thefile format of data that is read from the record medium and forreproducing the data when the file format of the data that has been readis the first file format, reading the reference file identificationinformation and the medium identification information or the informationof which the medium identification information has been converted fromthe reference information storing portion when the file format of thedata that has been read is the second file format, reading the mediumidentification information or the information of which the mediumidentification information has been converted and the reference fileinformation from the record medium, and determining whether or not themedium identification information or the information of which the mediumidentification information has been converted recorded in the referenceinformation storing portion matches the medium identificationinformation or the information of which the medium identificationinformation has been converted recorded on the record medium and forreading a file designated by the reference file information andreproducing the file when they match.

A seventh aspect of the present invention is a record medium on whichdigital data has been recorded, the record medium being removable andassigned unique medium identification information, the digital datahaving a file structure that allows a first file format and a secondfile format to be used, the first file format being handled by computersoftware and composed of a reference information storing portion and areal data storing portion, the second file format being composed of onlya reference information storing portion, reference file information andmedium identification information of the record medium or information ofwhich the medium identification information has been converted beingrecorded to at least the reference information storing portion of a filehaving the second file format.

According to the present invention, in the case of at least an externalreference file, in addition to the reference file information, mediumidentification information of a record medium or information of whichmedium identification information has been converted is recorded to areference information storing portion. Thus, with medium identificationinformation of an external-referenced type file, a medium can bechecked. When the medium identification information recorded in theexternal-referenced type file does not match the medium identificationinformation that is read from a record medium, it is clear that therecord medium does not record a file to be referenced.

The following US patents are prior patents of the present invention.

-   -   (1) U.S. Pat. No. 4,945,475    -   (2) U.S. Pat. No. 5,253,053    -   (3) U.S. Pat. No. 5,652,879

In addition, the applicant of the present invention has filed thefollowing Japanese patent applications.

-   -   (1) Japanese Patent Application No. 11-264630 filed on Sep. 17,        1999    -   (2) Japanese Patent Application No. 11-264631 filed on Sep. 17,        1999    -   (3) Japanese Patent Application No. 11-279993 filed on Sep. 30,        1999

These and other objects, features and advantages of the presentinvention will become more apparent in light of the following detaileddescription of a best mode embodiment thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the structure of an embodiment of thepresent invention;

FIG. 2 is a schematic diagram showing an example of a QuickTime fileformat according to the present invention;

FIGS. 3A and 3B are schematic diagrams for explaining the relationbetween GOPs of the MPEG video and a QuickTime file format according tothe embodiment of the present invention;

FIGS. 4A and 4B are schematic diagrams for explaining an example of therelation between compression-encoded audio data and a QuickTime fileformat according to the embodiment of the present invention;

FIGS. 5A and 5B are schematic diagrams for explaining another example ofthe relation between compression-encoded audio data and a QuickTime fileformat according to the embodiment of the present invention;

FIGS. 6A, 6B, 6C, and 6D are schematic diagrams for explaining therelation between GOPs of MPEG video data and a QuickTime file formataccording to the embodiment of the present invention;

FIGS. 7A, 7B, 7C, and 7D are schematic diagrams for explaining anotherexample of the relation between compression-encoded audio data and aQuickTime file format according to the embodiment of the presentinvention;

FIG. 8 is a schematic diagram for explaining an example of a recordingmethod for an optical disc according to the embodiment of the presentinvention;

FIG. 9 is a schematic diagram for explaining another example of therecording method for an optical disc according to the embodiment of thepresent invention;

FIG. 10 is a schematic diagram for explaining a concept of the presentinvention;

FIG. 11 is a schematic diagram for explaining an editing systemaccording to the present invention;

FIG. 12 is a flow chart for explaining a process upon storing a fileaccording to the embodiment of the present invention;

FIG. 13 is a flow chart for explaining a process upon reproducing a fileaccording to the embodiment of the present invention;

FIG. 14 is a schematic diagram for explaining the detailed datastructure of the movie resource portion according to the embodiment ofthe present invention;

FIG. 15 is a schematic diagram for explaining the detailed datastructure of the movie resource portion according to the embodiment ofthe present invention;

FIG. 16 is a schematic diagram for explaining an external-referencedtype file; and

FIG. 17 is a schematic diagram for explaining a problem to be solved bythe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the invention will now be described withreference to the drawings. FIG. 1 shows an example of the structure of adigital recording and reproducing apparatus according to the embodimentof the present invention. In FIG. 1, 1 denotes digital encoder. A videoinput is supplied to a video encoder 1. The video enoder 1compression-encodes the video signal. Thus, 2 denotes an audio encoder.As audio inputs of audio encoder 2, an audio signal iscompression-encoded. For example, MPEG is used for thecompression-encoding process toward video signals and audio signals. Theoutputs of video encoder 1 and audio encoder 2 are referred as theelement streams.

When MPEG is used, the video encoder 1 is composed of a motionpredicting portion, a picture sequence rearranging portion, asubtracting portion, a DCT portion, a quantizing portion, a variablelength code encoding portion, and a buffer memory. The motion predictingportion detects a moving vector. The subtracting portion forms apredictive error between an input picture signal and a locally decodedpicture signal. The DCT portion transforms an output signal of thesubtracting portion corresponding to the DCT method. The quantizingportion quantizes an output signal of the DCT portion. The variablelength encoding portion encodes an output signal of the quantizingportion into a signal having a variable length. The buffer memoryoutputs the encoded data at a constant data rate. The picture sequencerearranging portion rearranges the sequence of pictures corresponding tothe encoding process. In other words, the picture sequence rearrangingportion rearranges the sequence of pictures so that after I and Ppictures are encoded, a B picture is encoded. The local decoding portionis composed of an inverse quantizing portion, an inverse DCT portion, anadding portion, a frame memory, and a motion compensating portion. Themotion compensating portion performs all of a forward predictingoperation, a reverse predicting operation, and a bidirectionalpredicting operation. When the intra encoding process is performed, thesubtracting portion directly passes data, not performs the subtractingprocess. The audio encoder 2 comprises a sub-band encoding portion andan adaptively quantized bit allocating portion.

As an example, in the case of a portable disc recording and reproducingapparatus with a built-in camera, a picture photographed by the camerais input as video data. In addition, a voice collected by a microphoneis input as audio data. The video encoder 1 and the audio encoder 2convert analog signals into digital signals. According to the embodimentof the present invention, a rewritable optical disc is used as a recordmedium. Examples of such an optical disc are a magneto-optical disc anda phase-change type disc. According to the embodiment of the presentinvention, a magneto-optical disc having a relatively small diameter isused.

Output signals of the video encoder 1 and the audio encoder 2 aresupplied to a file generator 5. The file generator 5 converts outputsignals of the video encoder 1 and the audio encoder 2 into a videoelementary stream and an audio elementary stream so that they can behandled corresponding to a computer software program for synchronouslyreproducing a moving picture and a sound without need to use a dedicatedhardware portion. According to the embodiment of the present invention,for example, as such a software program, QuickTime is used. A sequenceof data (video data, audio data, and text data) that varies on time baseand that is process by QuickTime is referred to as QuickTime movie. Thefile generator 5 multiplexes encoded video data and encoded audio data.To generate a QuickTime movie file, a system controlling microcomputer 9controls the file generator 5.

QuickTime movie files generated by the file generator 5 are successivelywritten to a memory 7 through a memory controller 8. When the systemcontrolling microcomputer 9 issues a data write request for a disc tothe memory controller 8, the memory controller 8 reads a QuickTime moviefile from the memory 7. In this example, the transfer rate of theencoding process for a QuickTime movie file is lower than that for datawritten to the disc. For example, the former is half of the latter.Thus, although QuickTime movie files are successively written to thememory 7, they are intermittently read from the memory 7 under thecontrol of the system controlling microcomputer 9 in such a manner thatthe memory 7 is prevented from overflowing or underflowing.

A QuickTime movie file that is read from the memory 7 through the memorycontroller 8 is supplied to an error correction encoder/decoder 11. Theerror correction encoder/decoder 11 temporarily writes a QuickTime moviefile to a memory 10. The error correction encoder/decoder 11 performs aninterleaving process and an error correction code encoding process so asto generate redundant data. The error correction encoder/decoder 11reads the QuickTime movie file with redundant data from the memory 10.

Output data of the error correction encoder/decoder 11 is supplied to adata modulator/demodulator 13. When digital data is recorded on thedisc, the data modulator/demodulator 13 modulates the data in such amanner that a clock signal can be easily extracted so that data can berecorded on a disc free from a problem such as an inter-codeinterference. For example, RLL (1, 7) can be used.

An output signal of the data modulator/demodulator 13 is supplied to amagnetic field modulating driver 14. In addition, a signal for drivingan optical pickup 23 is output to the magnetic field modulating driver14. The magnetic field modulating driver 14 drives a magnetic field head22 corresponding to the input signal so as to apply a magnetic field toan optical disc 20. The optical pickup 23 radiates a recording laserbeam to the optical disc 20. In such a manner, data is recorded on theoptical disc 20. The optical disc 20 is rotated at CLV (Constant LinearVelocity), CAV (Constant Angular Velocity), or ZCAV (Zone CLV of whichthe disc surface area is divided into for example three areas in each ofwhich the optical disc 20 is rotated at CAV in such a manner that thevelocity of the innermost area is the highest and the velocity of theoutermost area is the lowest).

Since data that is intermittently read from the memory controller 8 isrecorded to the optical disc 20, data is not successively recorded. Inother words, after a predetermined amount of data is recorded, therecording operation is stopped until the next record request isreceived.

When the system controlling microcomputer 9 issues a request to a drivecontrolling microcomputer 12, it issues a request to a servo circuit 15so as to control the entire disc drive. Thus, the disc drive performs arecording operation. The servo circuit 15 performs a disc radial movingservo operation, a tracking servo operation, and a focus servo operationfor the optical pickup 23. In addition, the servo circuit 15 performs aspindle servo operation for a motor 21. In association with the systemcontrolling microcomputer 9, a user operation input portion (not shown)is disposed.

On the optical disc 20 as a blank disc, a unique disc ID (for example,serial number) has been recorded. For example, the disc ID has beenrecorded in the innermost peripheral area of the disc. The innermostperipheral area is a rewrite prohibition area. As will be describedlater, according to the present invention, a file is properly referencedwith the disc ID. In addition, the disc ID is often used to assure thatthe disc is a regal disc for copyright protection. In other words, whenthe optical disc 20 is inserted into a recorder, an authenticatingprocess is performed with the disc ID. When the disc ID has not beensubstantially recorded, the disc is treated as an illegal disc andthereby it is not successfully authenticated. As a result, data isprohibited from being recorded and/or reproduced to/from the disc. Froma view point of copyright protection, a structure of which the disc IDcannot be read to the outside of a device such as a recorder is used.Thus, the disc ID is not used as it is. Instead, the disc ID isconverted into for example a character string corresponding to apredetermined rule such as an encryption.

Next, the structure and operation of the reproducing portion will bedescribed. When data is reproduced, a reproducing laser beam is radiatedto the optical disc 20. A detector of the optical pickup 23 converts thereflected light of the optical disc 20 into a reproduction signal. Atracking error and a focus error are detected from an output signal ofthe detector of the optical pickup 23. The servo circuit 15 controls theoptical pickup 23 so that the optical pickup 23 is placed and focused ona desired track. In addition, the servo circuit 15 controls the radialmovement of the optical pickup 23 so that it reproduces data on adesired track of the optical disc 20.

As with the recording operation, when data is reproduced, the transferrate of data reproduced from the optical disc 20 is higher than that ofa QuickTime movie file. For example, the transfer rate of datareproduced form the optical disc 20 is twice as large as the transferrate of a QuickTime movie file. Likewise, data is not successivelyreproduced from the optical disc 20. In other words, an intermittentreproducing operation is performed in such a manner that after apredetermined amount of data is reproduced, the reproducing operation isstopped until the next reproducing request is received. As with therecording operation, in the reproducing operation, when the systemcontrolling microcomputer 9 issues a request to the drive controllingmicrocomputer 12, it issues a request to the servo circuit 15 so as tocontrol the entire disc drive.

The reproduction signal that is output from the optical pickup 23 isinput to the data modulator/demodulator 13. The datamodulator/demodulator 13 demodulates the reproduction signal. Thedemodulated data is supplied to the error correction encoder/decoder 11.The error correction encoder/decoder 11 temporarily writes thereproduction data to the memory 10. The error correction encoder/decoder11 performs a deinterleaving process and an error correcting process forthe reproduction data. The error-corrected QuickTime movie file iswritten to the memory 7 through the memory controller 8.

A QuickTime movie file written to the memory 7 is output to a filedecoder 6 in synchronization with a demultiplexing timing correspondingto a request issued by the system controlling microcomputer 9. Thesystem controlling microcomputer 9 supervises the amount of data that isreproduced from the optical disc 20 and written to the memory 7 and theamount of data that is read from the memory 7 and output to the filedecoder 6 so as to successively reproduce the video signal and the audiosignal. In addition, the system controlling microcomputer 9 controls thememory controller 8 and the drive controlling microcomputer 12 so as toread data from the optical disc 20 in such a manner that the memory 7does not overflow or underflow.

The file decoder 6 decodes a QuickTime movie file into a videoelementary stream and an audio elementary stream under the control ofthe system controlling microcomputer 9. The video elementary stream issupplied to a video decoder 3. The audio elementary stream is suppliedto an audio decoder 4. The video elementary stream and the audioelementary stream are synchronously output from the file decoder 6.

The video decoder 3 and the audio decoder 4 compression-decode the videoelementary stream and the audio elementary stream and generate a videooutput signal and an audio output signal, respectively. In this example,the video signal and the audio signal have been encoded corresponding toMPEG. A video output signal is output to a display (liquid crystaldisplay or the like) through a display driver and displayed as apicture. Likewise, an audio output signal is output to a speaker throughan audio amplifier and reproduced as a sound (these structural portionsare not shown).

The video decoder 3 is composed of a buffer memory, a variable lengthcode decoding portion, an inverse DCT portion, an inverse quantizingportion, an adding portion, and a local decoding portion. The addingportion adds an output signal of the inverse quantizing portion and alocal decoded output signal. The local decoding portion is composed of apicture sequence rearranging portion, a frame memory, and a motioncompensating portion. When an intra encoding process is performed, theadding portion directly passes data, not performs the adding process.Decoded data is output from the adding portion to the picture sequencerearranging portion. The picture sequence rearranging portion rearrangesthe decoded pictures in the original order.

As was described above, since the optical disc 20 on which data isrecorded is attachable and detachable, the data recorded on the opticaldisc 20 can be reproduced by another apparatus. For example, a personalcomputer that operates with QuickTime application software may read datarecorded on the optical disc 20 and reproduce video data and audio datatherefrom. It should be noted that the present invention can be appliedto an apparatus that handles only video data or only audio data.

Next, the embodiment of the present invention will be described in moredetail. First of all, with reference to FIG. 2, QuickTime will bedescribed in brief. QuickTime is an OS expansion function forreproducing a moving picture without need to use dedicated hardware.There are various data formats for QuickTime. In other words, audiodata, video data, MDI, and so forth of up to 32 tracks can besynchronously output.

A QuickTime movie file is roughly divided into two major portions thatare a movie resource portion and a movie data portion. The movieresource portion contains time data necessary for reproducing theQuickTime movie file and information necessary for referencing realdata. The movie data portion contains real data of video data and realdata of audio data.

One QuickTime movie file can contain different types of medium data suchas a sound, a video, and a text as independent tracks that are a soundtrack, a video track, and a text track, respectively. These independenttracks are strictly controlled on time base. Each track has a medium forreferencing the compression method of the real data and the display timeperiod thereof. The medium contains the minimum sample size of the realdata in the movie data portion, the position of a chunk that is a blockof a plurality of samples, and the display duration of each sample.

FIG. 2 shows an example of a QuickTime file that handles audio data andvideo data. The largest structural portions of the QuickTime file are amovie resource portion and a movie data portion. The movie resourceportion contains the duration necessary for reproducing the file anddata necessary for referencing the real data. The movie data portioncontains real data of video data, audio data, and so forth.

Next, the structure of the movie resource portion will be described indetail. The movie resource portion 50 has a hierarchical structure of aheader portion 50, a track portion 51, a media portion 52, a mediainformation portion 53, and a sample table portion 54. The headerportion 50 describes information about the entire file. The trackportion 51 describes information about each part of the movie data. Themedia portion 52 describes information about each part of data. Themovie resource portion is used for one video track. Likewise, oneQuickTime movie file contains a resource portion 55 for an audio track.The structure of the resource portion 55 is the same as the structure ofthe movie resource portion.

The header portion 50 contains a movie header 41. The track portion 51contains a track header 42 that describes general information about thetrack. The media portion 52 contains a media header 43 and a mediahandler 44. The media header 43 describes general information about themedia. The media handler 44 describes information for handling the mediadata. The media information portion 53 contains a media handler 45, adata handler 46, and data information portion 47. The media handler 45describes information about the picture media. The data handler 46describes information for handling the picture data. The datainformation portion 47 describes information about the data. The sampletable portion 54 contains a sample description, a time-to-sample, asample size 48, a sample-to-chunk, a chunk offset 49, a sync sample, andso forth. The sample description describes each sample. Thetime-to-sample describes the relation between samples and time base. Thesample size 48 describes the size of each sample. The sample-to-chunkdescribes the relation between samples and chunks. The chunk offset 49describes the start bit position of a chunk in the movie file. The syncsample describes information about synchronization.

On the other hand, the movie data portion 56 contains audio data encodedcorresponding to for example MPEG Audio Layer 2 and picture data encodedin the compression-encoding method corresponding to for example MPEGmethod in the unit of chunks each of which is composed of apredetermined number of samples. However, it should be noted that thepresent invention is not limited to such an encoding method. Inaddition, the moving data portion may contain linear data that has notbeen compression-encoded.

Each track of the movie resource portion is correlated with datacontained in the movie data portion. In other words, in the exampleshown in FIG. 2, since audio data and video data are handled, the movieresource portion contains a video track and an audio track. The moviedata portion contains real data of the audio data and real data of thevideo data. When other types of data are handled, the movie resourceportion contains their tracks and the movie data portion contains realdata thereof. For example, when a text and MIDI are handled, the movieresource portion contains tracks of the text and the MIDI and the moviedata portion contains real data thereof.

Next, a method for converting compressed video data (video elementarystream) and compressed audio data (audio elementary stream) into aQuickTime file format in the case that MPEG2 is used as a decodingmethod for data that has been compression-encoded will be described.First of all, MPEG will be described. MPEG has a hierarchical structureof six layers that are a sequence layer, a GOP layer, a picture layer, aslice layer, a macro block layer, and a block layer in the order of thehighest hierarchical level. A header is placed at the beginning of eachof the six layers. For example, a sequence header is a header placed atthe beginning of the sequence layer. The sequence header contains asequence start code, a horizontal screen size, a vertical screen size,an aspect ratio, a picture rate, a bit rate, a VBV buffer size, arestriction parameter bit, a load flag of two quantized matrixes, and acontent.

According to MPEG, there are three picture types I, P, and B. In an Ipicture (Intra-coded picture), when a picture signal is encoded,information of only one picture is used. Thus, when an encoded picturesignal is decoded, information of only the I picture is used. In a Ppicture (Predictive-coded picture), as a predictive picture (a referencepicture for obtaining a difference with the current P picture), an Ipicture or another P picture that has been decoded is temporallyfollowed by the current P picture. The difference between the current Ppicture and a motion-compensated predictive picture is encoded for eachmacro block. Alternatively, the current P picture is encoded for eachmacro block without obtaining the difference of such pictures. One ofthose methods is selected whichever higher efficiency is obtained. In aB picture (Bidirectionally predictive-coded picture), as predictivepictures (reference pictures for obtaining a difference with the currentB picture), three types of reference pictures are used. The first typereference picture is an I picture or a P picture that has been decodedand that is temporally followed by the current B picture. The secondtype reference picture is an I picture or a P picture that has beendecoded and that is temporally preceded by the current B picture. Thethird type reference picture is an interpolated picture of the firsttype reference picture and the second type reference picture. Thedifference between the current B picture and each of the three typereference pictures that have been motion-compensated is encoded for eachmacro block. Alternatively, the current B picture is encoded for eachmacro block without obtaining such a difference. One of those methods isselected whichever higher efficiency is obtained.

Thus, there are a frame intra-coded macro block, a forward inter-framepredictive macro frame (a future macro block is predicted with a pastmacro block), a backward inter-frame predictive macro block (a pastmacro block is predicted with a future macro block), and a bidirectionalmacro block (a current macro block is predicted with both a future macroblock and a past macro block). All macro blocks in an I picture areintra-frame coded macro blocks. A P picture contains intra-frame codedmacro blocks and forward inter-frame predictive macro blocks. A Bpicture contains the above-described four types of macro blocks.

In MPEG, a GOP (Group Of Pictures) structure that is a group of picturesis defined so that data can be random-accessed. In MPEG, a GOP isdefined as follows. The first picture of one GOP is an I picture. Thelast picture of one GOP is an I picture or a P picture. A GOP that ispredicted with the last I or P picture of the preceding GOP ispermitted. A GOP that can be decoded without a picture of the precedingGOP is referred to as closed GOP. According to the embodiment, as astructure of a closed GOP, each GOP can be edited.

In MPEG audio (compressing method), three modes of layer 1, layer 2, andlayer 3 have been defined. In layer 1, for example 32 sub-band encodingoperation and adaptive bit allocating operation are performed. One audiodecoding unit is composed of 384 samples. One audio decoding unit is oneaudio frame of an audio bit stream. The audio decoding unit is theminimum unit of which encoded data is decoded to audio data. Likewise,the video decoding unit corresponding to one video frame has beendefined. In NTSC system, one video frame is equivalent to {fraction(1/30)} seconds. Normally, the bit rate of stereo audio in layer 1 is256 kbps. In layer 2, a 32 sub-band encoding operation and an adaptivebit allocating operation are performed. One audio decoding unit iscomposed of 1152 samples. Normally, the bit rate of stereo audio inlayer 2 is 192 kbps.

The file generator 5 converts video data and audio data that have beencompressed corresponding to MPEG into a file structure corresponding tothe above-described QuickTime file format. FIGS. 3A and 3B show therelation among video frames, GOPs, and units of samples and chunks ofthe QuickTime file format. As was described above, one sample is theminimum unit of movie data. One chunk is a unit of which a plurality Ofsamples are collected as a block.

As shown in FIG. 3A, for example 15 video frames of an original videosignal are compression-encoded corresponding to MPEG2 and thereby oneGOP is generated. 15 video frames are equivalent to 0.5 seconds. EachGOP is preferably structured as a closed GOP. A sequence header isplaced at the beginning of each GOP. The sequence header and one GOPcompose one video decoding unit. Since a sequence header is placed toeach GOP, each sample can be directly edited and decoded with QuickTime.The video encoder 1 shown in FIG. 1 outputs an MPEG video elementarystream shown in FIG. 3A.

As shown in FIG. 3B, one video decoding unit is treated as one sample ofthe QuickTime file format. Six chronologically successive samples (forexample, sample #0 to sample #5) are treated as one video chunk (forexample, chunk #0). The duration of one chuck is 3 seconds.Alternatively, six GOPs may be treated as one video chunk so that onechuck corresponds to one sample. In this case, the duration of one chuckis 3 seconds.

FIG. 4 shows the relation among audio frames encoded corresponding toMPEG audio layer 2, GOPs, and units of samples and chunks in theQuickTime file format. In layer 2, 1152 audio samples/channel aretreated as one audio frame. As shown in FIG. 4A, in stereo, 1152 audiosamples×2 channels are encoded in layer 2 and treated as one audiodecoding unit. One audio decoding unit contains data of 384 bytes×2channels that have been compression-encoded. The audio decoding unitcontains a header and information necessary for decoding the encodeddata (allocation, scale factor, and so forth).

As shown in FIG. 4B, one audio decoding unit is treated as one sample ofthe QuickTime file format. Thus, each audio sample can be decoded withQuickTime. 125 chronological successive samples (for example, sample #0to sample #124) are treated as one audio chunk (for example, chuck #0).The duration of one chuck is 3 seconds in the case that the audiosampling frequency is 48 kHz.

In FIGS. 3 and 4, a video data file and an audio data file areseparately shown. The file generator 5 multiplexes a video data file andan audio data file as one data stream and thereby generates a QuickTimemovie file. In the QuickTime movie file, video chunks and audio chucksare alternatively placed on time base. In this case, video chunks andaudio chunks are placed in such a manner that a video chuck adjacents toan audio chunk corresponding thereto. As was described above, theduration of video data of one video chunk is equal to the duration ofaudio data of one audio chunk (for example, 3 seconds).

As another example of the audio compression-encoding method, ATRAC(Adaptive Transform Acoustic Coding) used for Mini Disc may be used. InATRAC, audio data of 16 bits sampled at 44.1 kHz is processed. Theminimum data unit processed in ATRACK is one sound unit. In stereo, onesound unit is composed of 512 samples×16 bits×2 channels.

When ATRAC is used as an audio compression-encoding method, as shown inFIG. 5A, one sound unit is compressed to an audio decoding unit of 212bytes×2 channels. As shown in FIG. 5B, one audio decoding unit istreated as one sample in the QuickTime file format. 64 samples aretreated as one chunk in the QuickTime file format.

According to the present invention, the audio data may be recorded on anon-compression basis. The non-compression method is referred to aslinear PCM. Likewise, in linear PCM, 512 audio samples are treated asone audio decoding unit. One audio decoding unit is treated as onesample in the QuickTime file format.

FIG. 6 shows a QuickTime file format for video data in the case thatvideo data and audio data are multiplexed. As shown in FIG. 6A, theperiod of a video frame is t0 seconds and the number of frames of oneGOP is f0. When original video data is encoded corresponding to MPEG2,an MPEG video elementary stream shown in FIG. 6B is formed. As wasdescribed above, a sequence header (SH) is placed to each GOP.

As shown in FIG. 6C, one GOP with a sequence header is treated as onesample in the QuickTime file format. The length of one sample isreferred to as sample size. With a plurality of samples (for example,six samples), one chunk is composed in the QuickTime file format. Asshown in FIG. 6D, video chunks and audio chunks are alternately placedon time base and thereby multiplexed. As a result, a QuickTime moviefile is formed. The beginning of each video chunk of the QuickTime moviefile is referred to as video chunk offset. The video chunk offset isrepresented by the number of bytes from the beginning of the file to thebeginning of the video chunk.

FIG. 7 shows a QuickTime file format of audio data in the case thatvideo data and audio data are multiplexed. As shown in FIG. 7A, anoriginal audio signal is digitized. One audio frame contains f0 audiosamples×n channels. When the original audio data is compression-encodedcorresponding to MPEG audio, an MPEG audio elementary stream shown inFIG. 7B is formed.

As shown in FIG. 7C, for example one audio decoding unit is treated asone sample of the QuickTime file format. The size of one sample isreferred to as sample size. A plurality of samples (for example, 125samples) composes one chunk of the QuickTime file format. As shown inFIG. 7D, video chunks and audio chunks are alternately placed andthereby multiplexed. As a result, a QuickTime movie file is formed. Thebeginning of each audio chunk of a QuickTime movie file is referred toas audio chunk offset. The audio chunk offset is represented by thenumber of bytes from the beginning of the file to the beginning of theaudio chunk. The duration of each video chunk is the same as theduration of each audio chunk. For example, the duration is 3 seconds.

The sample size of a video sample, the sample size of an audio sample,the offset value of a video chunk, and the offset value of an audiochunk are contained in the resource of a QuickTime movie file. With theresource, each sample of each chunk can be designated and edited (in theencoding unit).

Next, as mentioned above, a recording method for recording a QuickTimemovie file of which video chunks and audio chunks have been multiplexed(interleaved) to the optical disc 20 will be described. As describedabove, one QuickTime file format is roughly divided into two majorportions that are a movie resource portion and a movie data portion.When a QuickTime movie file is recorded to the optical disc 20, as shownin FIG. 8, the movie resource is matched with the successive recordlength. In addition, each chunk (video chunk or audio chunk) of themovie data (real data) is matched with the successive record length ofthe disc. The successive record length means the length of which datacan be written to successive addresses without a jumping operation ofthe optical pickup 23.

FIG. 9 shows another example of which a QuickTime movie file is recordedon the optical disc 20. As described above, when video chunks and audiochunks have been multiplexed, a pair of an audio chunk and an adjacentvideo that corresponds thereto is matched with the successive recordlength.

As shown in FIGS. 8 and 9, the position of the successive record lengthis physically not continuous. Thus, after the movie resource isreproduced, when the first audio chunk and video chunk are reproduced(namely, data of two successive record lengths is reproduced), a trackjump takes place. However, as was described above, since the datatransfer rate of write/read operation is higher (for example, two timeshigher) than the data transfer rate of a QuickTime movie file, even ifdata is intermittently read, successive QuickTime movie files can bereproduced.

Thus, the transfer rate of a QuickTime movie file, the read rate of datafrom the optical disc, the duration of the successive record length, andthe seek time of the disc drive (the seek time is the duration necessaryfor a track jump from one track to another track) mutually relate. Thus,the duration of video data and audio data recorded in the successiverecord length can be selected in various manners from other than 3seconds. It is preferred that in the duration for video frames of videodata recorded in the successive record length, an integer number ofaudio samples are placed.

When the duration of video data and the duration of audio data recordedas the above-described successive record length are not fixed, thesuccessive record length is described in the movie resource portion ofthe QuickTime movie file. The successive record length is described asfor example the number of frames of one video chunk and the number ofsamples of one audio chunk. In addition, information that representsthat two or more different types of data such as video data and audiodata have been successively recorded is stored in the file. In theabove-described example, sets of an audio chunk and a video chunk aresuccessively recorded. In the case of QuickTime, information thatrepresents a set of tracks is described in user-defined data atom. Theuser-defined data atom is described in a hierarchy of the header portion50 or the track portion 51 shown in FIG. 2.

According to the present invention, as with the above-describedQuickTime, a file in a structure that allows an external-referenced typefile that contains only a resource portion to exist is edited on apersonal computer. When the edited result is copied or moved to anoptical disc in the external-referenced type file format, a problem ofwhich the same identification information takes place is solved. FIG. 10shows a concept of the present invention. On the optical disc 20, aunique disc ID has been recorded. A movie file 61 has been recorded in aself-contained type file format on the optical disc 20.

When a file 62 containing only a movie resource portion references themovie file 61 corresponding to the reference file information, the discID is used. In other words, the resource portion of the file 62 containsthe disc ID (or a unique character string converted from the disc ID aswas described above). When the file is stored, the disc ID is obtained.The disc ID of the resource portion is compared with the disc ID that isread from the optical disc 20. When they match, it is determined thatthe file 62 is a file referenced by the movie file 61. When they do notmatch, it is determined that the file 62 is not a file referenced by themovie file 61. A relevant alarm is issued.

FIG. 11 shows a system that performs an editing process according to thepresent invention. In FIG. 11, reference numeral 71 represents anexternal optical disc drive device (or a recorder such as a discrecording and reproducing apparatus having a built-in camera). Theexternal drive device 71 is connected to a personal computer 70. Forexample, an optical disc 20 a is inserted into the external drive device71. A plurality of files recorded on the optical disc 20 a are copied ormoved to a hard disk 72 of the personal computer 70. Real data (moviedata) of files is not read to the personal computer 70. Instead, onlyreference information (movie resource portion) is read to the personalcomputer 70.

Multimedia software such as QuickTime is pre-installed to the personalcomputer 70. The user performs an editing operation using the softwareand copies or moves the edited result to the optical disc. The editedresult is recorded in an external-referenced type file format to theoptical disc. When the edited result is stored, the disc ID of theoptical disc 20 a having a file to be referenced is written to thereference information storing portion of the external-referenced typefile.

The edited result may be mistakenly restored to another optical disc 20b instead of the original optical disc 20 a. In addition, the editedresult may be stored in the personal computer 70. The personal computer70 may reproduce a program using a file recorded on an optical disc. Inthis case, the original optical disc 20 a may be replaced with anotheroptical disc 20 b.

When a recorder or the personal computer 70 reproduce data from anoptical disc on which the edited result has been recorded, the recorderor the personal computer 70 checks for the optical disc with a disc ID.In other words, it is determined whether or not the disc ID stored inthe file 62 as the edited result matches the disc ID that is read fromthe disc. When the disc is the original disc 20 a, they match. Thus,data reproduction is permitted. In contrast, when the disc is anotheroptical disc 20 b, since both disc IDs do not match, data reproductionis prohibited. In this case, a relevant alarm is issued. In such amanner, a problem of which the same file name (reference fileinformation) exists in files stored in the optical discs 20 a and 20 b,the edited result causes such files to be referenced, and data isreproduced from such an unintended file can be prevented.

FIG. 12 is a flow chart showing a process for storing a file performedby the personal computer 70 in the editing system shown in FIG. 11. Atstep S1, a movie file 1 is read from a disc. At step S2, the movie file1 is edited. For example, the movie file 1 is divided into two files.

At step S3, it is determined whether or not the edited result is storedas an external-referenced type file as a different file. When thedetermined result at step S3 is No, the flow advances to step S4. Atstep S4, the edited result is stored as a self-contained type file.Thereafter, the process is completed. When the determined result at stepS3 is Yes (namely, the edited result is stored as an external-referencedtype file), a unique disc ID of a disc to which the file is stored isread (at step S5).

At step S6, the disc ID that has been read is converted into an uniquecharacter string of the ID. Since the disc ID is often used forcopyright protection, it is not preferable to allow the disc ID—forexample—a serial number to be read to the outside of the personalcomputer or the recorder from a view point of security. Thus, the discID is converted into a different character string. Alternatively, thedisc ID may be encrypted.

At step S7, the edited result is stored as an external-referenced typefile. In other words, in addition to the reference file name (absolutepath), a unique character string of the ID is written to theexternal-referenced type file. Thereafter, the process is completed.

Next, with reference to a flow chart shown in FIG. 13, a process forreproducing a stored file will be described. The process shown in FIG.13 is performed by an external drive device, the personal computer 70 towhich a recorder is connected, or a recorder. At step S21, the moviefile 1 to be reproduced is read from the disc. Thereafter, it isdetermined whether or not the movie file 1 is an external-referencedtype file (at step S22).

When the movie file 1 is a self-contained type file, the flow advancesto step S23. At step S23, the movie file 1 is reproduced as aself-contained type file. Thereafter, the process is completed. When thedetermined result at step S22 is Yes (namely, the movie file 1 is anexternal-referenced type file), the flow advances to step S24. At stepS24, the reference file name (absolute path) and the unique characterstring 1 of the ID are read from the movie file 1.

Thereafter, the flow advances to step S25. At step S25, the unique ID isread from the disc. Thereafter, the flow advances to step S26. At stepS26, the ID is converted into a unique character string 2 of the ID.Thereafter, the flow advances to step S27. At step S27, it is determinedwhether or not the unique character string 1 of the ID that has beenread from the movie file 1 matches the unique character string 2 of theID that has been read from the disc. When they do not match, the flowadvances to step S30. At step S30, the user is informed of a messagethat represents that the disk does not store the file to be referenced.Thereafter, the process is completed.

When the determined result at step S27 is Yes (namely, the characterstring 1 matches the character string 2), the flow advances to step S28.At step S28, a file to be referenced is read from the disc. The moviefile 1 is reproduced with the reference file stored on the disc.Thereafter, the process is completed.

In the example of QuickTime, the movie resource portion is a referenceinformation storing portion. The resource portion contains referencefile information and a disc ID or a character string created with thedisc ID. FIGS. 14 and 15 shows the detailed data structure of the moveresource portion of QuickTime. FIGS. 14 and 15 show a first portion anda second portion of the data structure of the move resource portion ofQuickTime.

As was described with reference to FIG. 2, the movie resource portionhas a hierarchical structure of the header portion 50, the track portion51, the media portion 52, media information portion 53, and the sampletable portion 54. The track portion 51 describes information aboutindividual data parts of the movie data. The media portion 52 describesinformation about individual data parts. As was described above, themovie resource portion is used for one video track. Likewise, the audioresource portion 55 (not shown) is used for one audio track. Thestructure of the movie resource portion 50 is the same as the structureof the audio resource portion 55.

As shown in FIG. 15, the media information portion 53 contains a datainformation portion 47. The data information portion 47 containsreference file information (file name) that represents a file to bereferenced. In addition to the reference file information, the disc ID(or a unique character string created with the disc ID) is written tothe data information portion 47.

In the above description, the present invention is applied to a discrecording and reproducing apparatus having a built-in camera. However,it should be noted that the present invention can be applied to otherapparatuses. In other words, the present invention can be applied to forexample a digital still camera and a digital audio recorder/player. Inaddition to an optical disc as a record medium, the present inventioncan be applied to a memory card composed of a flash memory. The memorycard has a file management area that is separated from a data file. Inaddition, for copyright protection, a memory card may store uniquemedium identification information. The present invention can be appliedto such a memory card.

In addition, according to the present invention, part or all thehardware structure shown in FIG. 1 may be accomplished by software.Moreover, the software is stored in a record medium that can be read bya computer. An example of such a record medium is a CD-ROM.

In the above-mentioned embodiment, QuickTime was described. In addition,the present invention can be applied to computer software that allows asequence of data that varies in a plurality of time sequences to besynchronously reproduced without need to use dedicated hardware.

According to the present invention, in addition to reference fileinformation that designates a file that an external-referenced type filereferences, the unique medium ID of a record medium that has a file thatis referenced or a description created with the medium ID are written.According to the present invention, when an external reference file isreproduced, with reference to a medium ID or a description created withthe medium ID, when data is reproduced from the external reference file,it can be determined whether or not the record medium has a file to bereferenced. Thus, the edited result can be prevented from designating anunintended file.

Although the present invention has been shown and described with respectto a best mode embodiment thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention.

1-12. (canceled)
 13. A reproducing apparatus for reproducing digitaldata from a record medium that is removable and assigned unique mediumidentification information, the digital data having a file structurethat allows a first file format and a second file format to be used, thefirst file format being handled by computer software and composed of areference information storing portion and a real data storing portion,the second file format being composed of only a reference informationstoring portion, reference file information and medium identificationinformation of the record medium or information of which the mediumidentification information has been converted being recorded to at leastthe reference information storing portion of a file having the secondfile format, comprising: means for determining the file format of datathat is read from the record medium and for reproducing the data whenthe file format of the data that has been read is the first file format;means for reading the reference file identification information and themedium identification information or the information of which the mediumidentification information has been converted from the referenceinformation storing portion when the file format of the data that hasbeen read is the second file format; means for reading the mediumidentification information or the information of which the mediumidentification information has been converted and the reference fileinformation from the record medium; and means for determining whether ornot the medium identification information or the information of whichthe medium identification information has been converted recorded in thereference information storing portion matches the medium identificationinformation or the information of which the medium identificationinformation has been converted recorded on the record medium and forreading a file designated by the reference file information andreproducing the file when they match, wherein unintended files areprevented from being referenced during recording of data.